texas height modernization dr. gary jeffress, rpls texas spatial reference center national height...
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Texas Height Modernization
Dr. Gary Jeffress, RPLSTexas Spatial Reference Center
National Height Modernization Partner MeetingNOAA Gulf of Mexico Disaster Response Center
Mobile, Alabama – April 2014
Recent Projects
• 2012-2013 GPS Precise Network Observations Along the Texas Gulf Coast– TCOON Tide gauge Benchmarks– Historic USACE tidal benchmarks– Texas CORS– GPS-able NGS first & second order Benchmarks
• A total of 72 network sessions and 153 stations observed (Adjust and Pages)
• All stations Bluebooked• Funded by US Army Corps of Engineers
2012-2013 GPS Precise Network Observations Along the Texas Gulf Coast
2013-2014 GPS Precise Network ObservationsAlong the Florida Gulf Coast
CORS on Tide Gauges Florida
Pensacola, FL
CORS on Tide Gauges Florida
Fernandina, FL
CORS on Tide Gauges Florida
St. Petersburg, FL
CORS on Tide Gauges Florida
Cedar Key, FL
CORS on Tide Gauges TexasExisting CORS 4
(USACE 2,NERRS 1,USFW 1)Proposed
Sentinel CORS 4(USFW)
Proposed Height Mod.
CORS 5TOTAL 13
Sentinel
The need for accurate Elevation in Texas
Austin, 1991Houston, 2001
Lives are lost and $Billions of property are lost.
National Flood Statistics (2001)From http://floodsafety.com/national/life/statistics.htm
Licensed Surveyor’s Role
13Up to 80% of these benchmarks have disappeared
Answer: The data are old and subject to change and destruction.
Why are Elevations so bad?
Why are Elevations Important?An Example from Galveston Bay, Texas
An Example from Galveston Bay, TexasFrom Google Street View
An Example from Galveston Bay, Texas
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From Google Maps
An Example from Galveston Bay, Texas
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An Example from Galveston Bay, Texas
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An Example from Galveston Bay, Texas
An Example from Galveston Bay, Texas
FF = Finished Floor LevelFF = 13.86 feet
FIRM September 1999Zone AE EL 12 = 12.00 feet
FIRM September 2012Zone AE EL 15 = 15.00 feet
An Example from Galveston Bay, Texas
Surveyor’s Elevation Datum
Flood Insurance Quote
For Sale $1,028,697 ?
Thank you for [email protected]